{"id":4,"date":"2013-08-17T01:51:25","date_gmt":"2013-08-16T17:51:25","guid":{"rendered":"http:\/\/blog.stlover.org\/?p=4"},"modified":"2013-08-24T07:09:56","modified_gmt":"2013-08-23T23:09:56","slug":"%e5%86%b3%e7%ad%96%e6%a0%91%e7%ae%97%e6%b3%95%e5%88%9d%e5%b0%9d","status":"publish","type":"post","link":"http:\/\/blog.xuhao1.me\/?p=4","title":{"rendered":"\u51b3\u7b56\u6811\u7b97\u6cd5\u521d\u5c1d\u4e4bID3"},"content":{"rendered":"

\u6700\u8fd1\u5b66\u4e60Machine Learning \uff0c\u53d1\u89c9\u9887\u4e3a\u6709\u8da3\u3002\u51c6\u5907\u4f7f\u7528\u76f8\u5173\u7b97\u6cd5\u6765\u8dd1\u4e00\u8dd1\u57fa\u56e0\u7ec4\uff0c\u505a\u505a\u673a\u5668\u4eba\u7684\u63a7\u5236\u3002<\/p>\n

\u51b3\u7b56\u6811\u662f\u4e00\u79cd\u9887\u4e3a\u6709\u8da3\u7684\u4e1c\u897f\uff0c\u5176\u57fa\u672c\u539f\u7406\u662f\u6240\u8c13\u7684Occam’s razor\uff1a\u4f18\u5148\u9009\u62e9\u62df\u5408\u6570\u636e\u6700\u7b80\u5355\u7684\u5047\u8bbe\u3002\u4e8e\u662f\u81ea\u7136\u7684\u5728java\u4e0a\u5199\u4e86\u4e2a\u51b3\u7b56\u6811\u73a9\u73a9\u3002<\/p>\n

<\/p>\n

\u5e9f\u8bdd\u5c11\u8bf4\uff0c\u770b\u770b\u6709\u8da3\u7684\u4ee3\u7801<\/p>\n

    \n
  1. ID3<\/span>(<\/span>String<\/span>[][]<\/span>\u00a0data<\/span>,<\/span>boolean<\/span>[]<\/span>\u00a0value<\/span>)<\/span>\u00a0<\/span>throws<\/span>\u00a0<\/span>IOException\/\/\u901a\u8fc7\u4e00\u5806String\u548c\u4e00\u4e2abool\u6570\u7ec4\u5efa\u7acb\u8fd9\u4e2a\u51b3\u7b56\u6811\uff0clog\u662f\u4e00\u4e9b\u8c03\u8bd5\u4fe1\u606f<\/span><\/li>\n
  2. \u00a0\u00a0\u00a0\u00a0<\/span>{<\/span><\/li>\n
  3. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>int<\/span>\u00a0i<\/span>,<\/span>n<\/span>;<\/span><\/li>\n
  4. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0log<\/span>=<\/span>new<\/span>\u00a0<\/span>PrintWriter<\/span>(<\/span>new<\/span>\u00a0<\/span>FileWriter<\/span>(<\/span>new<\/span>\u00a0<\/span>File<\/span>(<\/span>“fout.txt”<\/span>)),<\/span>true<\/span>);<\/span><\/li>\n
  5. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>Set<\/span><<\/span>obje<\/span>><\/span>\u00a0dat<\/span>=<\/span>new<\/span>\u00a0<\/span>HashSet<\/span><<\/span>obje<\/span>>();\/\/Set \u5de8\u597d\u7528\uff01<\/span><\/li>\n
  6. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>for<\/span>(<\/span>i<\/span>=<\/span>0<\/span>;<\/span>i<\/span><<\/span>data<\/span>.<\/span>length<\/span>;<\/span>i<\/span>++)<\/span><\/li>\n
  7. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0dat<\/span>.<\/span>add<\/span>(<\/span>new<\/span>\u00a0obje<\/span>(<\/span>data<\/span>[<\/span>i<\/span>],<\/span>value<\/span>[<\/span>i<\/span>]));<\/span><\/li>\n
  8. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0root<\/span>=<\/span>new<\/span>\u00a0node<\/span>(<\/span>dat<\/span>);<\/span><\/li>\n
  9. \u00a0\u00a0\u00a0\u00a0<\/span>}<\/span><\/li>\n<\/ol>\n

    ID3\u662f\u4e00\u79cd\u6700\u539f\u59cb\u7684\u51b3\u7b56\u6811\uff0c\u4e5f\u5c31\u662f\u6211\u4eec\u4eca\u5929\u8c08\u8bba\u7684\u5bf9\u8c61\u3002<\/p>\n

    \u5199\u5728\u51b3\u7b56\u6811\u65f6\u5019\uff0c\u6211\u662f\u8fd9\u4e48\u641e\u9012\u5f52\u5efa\u7acb\u8fc7\u7a0b\u3002<\/span><\/p>\n

      \n
    1. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0node<\/span>(<\/span>Set<\/span><<\/span>obje<\/span>><\/span>\u00a0data<\/span>)<\/span><\/li>\n
    2. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>{<\/span><\/li>\n
    3. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>int<\/span>\u00a0i<\/span>=<\/span>0<\/span>,<\/span>j<\/span>,<\/span>tem<\/span>=<\/span>0<\/span>,<\/span>n<\/span>;<\/span><\/li>\n
    4. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>double<\/span>\u00a0max<\/span>=<\/span>0<\/span>;<\/span><\/li>\n
    5. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0obje\u00a0top<\/span>=<\/span>data<\/span>.<\/span>iterator<\/span>().<\/span>next<\/span>();<\/span><\/li>\n
    6. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0n<\/span>=<\/span>top<\/span>.<\/span>numv<\/span>;<\/span><\/li>\n
    7. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0no<\/span>=++<\/span>num;\/\/\u8282\u70b9\u7f16\u53f7\uff0c\u65b9\u4fbfdebug<\/span>
      \n<\/span><\/li>\n
    8. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span>(<\/span>sam<\/span>(<\/span>data<\/span>))\/\/\u5982\u679c\u7ed3\u8bba\u76f8\u540c\uff0c\u90a3\u4e48\u5c31\u5f00\u5fc3\u7684\u5f97\u51fa\u51b3\u7b56\u6811\u7684\u51b3\u7b56\u5566<\/span><\/li>\n
    9. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>{<\/span><\/li>\n
    10. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0res<\/span>=<\/span>data<\/span>.<\/span>iterator<\/span>().<\/span>next<\/span>().<\/span>res<\/span>;<\/span><\/li>\n
    11. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>return<\/span>;<\/span><\/li>\n
    12. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>}<\/span><\/li>\n
    13. \u00a0<\/span><\/li>\n
    14. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>double<\/span>\u00a0gas<\/span>;<\/span><\/li>\n
    15. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>for<\/span>(<\/span>i<\/span>=<\/span>0<\/span>;<\/span>i<\/span><<\/span>n<\/span>;<\/span>i<\/span>++)<\/span><\/li>\n
    16. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span>(!<\/span>top<\/span>.<\/span>seleted<\/span>[<\/span>i<\/span>])\/\uff0f\u8fd9\u4e2a\u9009\u9879\u9009\u8fc7\u4e86\u90a3\u4e48\u5c31\u4e0d\u8981\u5b83\u4e86<\/span><\/li>\n
    17. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>{<\/span><\/li>\n
    18. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0gas<\/span>=<\/span>Gain<\/span>(<\/span>data<\/span>,<\/span>i<\/span>);\/\/\u9009\u4e00\u4e2a\u4fe1\u606f\u589e\u76ca\u6700\u597d\u7684\u70b9<\/span><\/li>\n
    19. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span>(<\/span>max<\/span><<\/span>gas<\/span>)<\/span><\/li>\n
    20. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>{<\/span><\/li>\n
    21. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0max<\/span>=<\/span>gas<\/span>;<\/span><\/li>\n
    22. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0tem<\/span>=<\/span>i<\/span>;<\/span><\/li>\n
    23. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>}<\/span><\/li>\n
    24. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>}<\/span><\/li>\n
    25. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0item<\/span>=<\/span>tem<\/span>;<\/span><\/li>\n
    26. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span>(<\/span>max<\/span><<\/span>1e-4<\/span>)\/\/\u5982\u679c\u4fe1\u606f\u589e\u76ca\u90fd\u592a\u5c0f\u5c31\u65e0\u53ef\u53ef\u9009\u4e86\uff0c\u5012\u6709\u53ef\u80fd\u662f\u6570\u636e\u6709\u8bef\u5dee\u6216\u8005\u9519\u8bef\uff0c\u6b64\u5904\u662fID3\u57fa\u672c\u7b97\u6cd5\u7684\u5c40\u9650\u7684\uff0c\u5728\u6539\u8fdb\u4e2d\u6b64\u884c\u5e94\u8be5\u628a\u7ed3\u8bba\u4ee5\u6982\u7387\u5f62\u5f0f\u7ed9\u51fa<\/span><\/li>\n
    27. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>return<\/span>;<\/span><\/li>\n
    28. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>HashMap<\/span><<\/span>String<\/span>,<\/span>HashSet<\/span><<\/span>obje<\/span>><\/span>\u00a0<\/span>><\/span>\u00a0lf<\/span>=<\/span>new<\/span>\u00a0<\/span>HashMap<\/span><<\/span>String<\/span>,<\/span>HashSet<\/span><<\/span>obje<\/span>>>();\/\/\u4e00\u4e2amap\u62d6\u4e00\u4e2aset\uff0c\u662f\u7528\u6765\u9020\u6811\u7684\uff0c\u51b3\u7b56\u6811\u4ee5\u540e\u96be\u514d\u9047\u5230\u53ef\u6015\u7684\u60c5\u51b5\uff0c\u8fd8\u662f\u63d0\u524dhash\u4e86\u4fdd\u8bc1\u901f\u5ea6\u5b89\u5168<\/span><\/li>\n
    29. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>for<\/span>(<\/span>obje\u00a0ij<\/span>:<\/span>data<\/span>)\/\/for_each\u6bcf\u4e2a\u9009\u9879<\/span><\/li>\n
    30. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span>(<\/span>lf<\/span>.<\/span>get<\/span>(<\/span>ij<\/span>.<\/span>field<\/span>[<\/span>item<\/span>])==<\/span>null<\/span>)\/\/\u662f\u7a7a\u7684\u5c31\u628a\u5b83\u653e\u5230\u5bf9\u5e94\u9009\u9879\u7684\u96c6\u5408\u4e0b\u3002<\/span><\/li>\n
    31. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>{<\/span><\/li>\n
    32. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>HashSet<\/span><<\/span>obje<\/span>><\/span>\u00a0bra<\/span>=<\/span>new<\/span>\u00a0<\/span>HashSet<\/span><<\/span>obje<\/span>>();<\/span><\/li>\n
    33. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ij<\/span>.<\/span>seleted<\/span>[<\/span>item<\/span>]=<\/span>true<\/span>;<\/span><\/li>\n
    34. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0bra<\/span>.<\/span>add<\/span>(<\/span>ij<\/span>);<\/span><\/li>\n
    35. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0lf<\/span>.<\/span>put<\/span>(<\/span>ij<\/span>.<\/span>field<\/span>[<\/span>item<\/span>],<\/span>bra<\/span>);<\/span><\/li>\n
    36. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>}<\/span><\/li>\n
    37. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>else\/\/\u7a7a\u7684\u5c31\u521b\u9020\u4e00\u4e2a\u96c6\u5408<\/span><\/li>\n
    38. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>{<\/span><\/li>\n
    39. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0ij<\/span>.<\/span>seleted<\/span>[<\/span>item<\/span>]=<\/span>true<\/span>;<\/span><\/li>\n
    40. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0lf<\/span>.<\/span>get<\/span>(<\/span>ij<\/span>.<\/span>field<\/span>[<\/span>item<\/span>]).<\/span>add<\/span>(<\/span>ij<\/span>);<\/span><\/li>\n
    41. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>}<\/span><\/li>\n
    42. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span><\/li>\n
    43. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>Set<\/span><<\/span>Map<\/span>.<\/span>Entry<\/span><<\/span>String<\/span>,<\/span>HashSet<\/span><<\/span>obje<\/span>>>><\/span>\u00a0lfs<\/span>=<\/span>lf<\/span>.<\/span>entrySet<\/span>();\/\/\u54c8\uff5e\u9887\u4e3a\u5947\u8469\u7684\u5efa\u6811\u65b9\u6cd5\uff0c\u7528\u4e00\u4e2amap\u89e3\u51b3\uff0c\u8fd9\u6837\u6811\u6709\u51e0\u4e07\u4e2a\u5206\u5c94\u4e5f\u4e0d\u6015\uff01\u5144\u5f1f\u5b69\u5b50\u8868\u793a\u6548\u7387\u4e0d\u9ad8\u7684<\/span><\/li>\n
    44. \u00a0<\/span><\/li>\n
    45. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>for<\/span>(<\/span>Map<\/span>.<\/span>Entry<\/span><<\/span>String<\/span>,<\/span>HashSet<\/span><<\/span>obje<\/span>>><\/span>\u00a0entry<\/span>:<\/span>lfs<\/span>)<\/span><\/li>\n
    46. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0leaf<\/span>.<\/span>put<\/span>(<\/span>\u00a0entry<\/span>.<\/span>getKey<\/span>(),<\/span>new<\/span>\u00a0node<\/span>(<\/span>entry<\/span>.<\/span>getValue<\/span>())<\/span>\u00a0<\/span>);<\/span>\u00a0\u00a0\u00a0\u00a0<\/span><\/li>\n
    47. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>}<\/span><\/li>\n
    48. \u00a0\u00a0\u00a0\u00a0<\/span>}<\/span><\/li>\n<\/ol>\n

      \u4e8e\u662f\u5462\uff0c\u6211\u7684\u5efa\u7acb\u6811\u7684\u4efb\u52a1\u5c31\u7528new node\u8fd9\u79cd\u6765\u5b9e\u73b0\u4e86\uff0c\u867d\u7136\u8fd9\u662f\u4e00\u4e2a\u6280\u672f\u95ee\u9898\uff0c\u4f46\u662f\u5fcd\u4e0d\u4f4f\u591a\u63d0\u4e00\u53e5\uff0c\u53d1\u73b0\u9762\u5bf9\u5bf9\u8c61\u7f16\u7a0b\u548c\u51fd\u6570\u5f0f\u7f16\u7a0b\u9887\u6709\u5f02\u66f2\u540c\u5de5\u4e4b\u5999\u8bf6<\/p>\n

      \u6bd4\u5982\uff0c\u5982\u4e0b\u662f\u6211\u7684haskell\u4e8c\u53c9\u6811\u7684\u5efa\u7acb<\/p>\n

        \n
      1. —<\/span>\u00a0<\/span>this<\/span>\u00a0is\u00a0haskell\u00a0code<\/span><\/li>\n
      2. insert\u00a0<\/span>::<\/span>\u00a0<\/span>(<\/span>Ord<\/span>\u00a0a<\/span>)<\/span>\u00a0<\/span>=><\/span>\u00a0a<\/span>-><\/span>\u00a0<\/span>Tree<\/span>\u00a0a<\/span>-><\/span>\u00a0<\/span>Tree<\/span>\u00a0a<\/span><\/li>\n
      3. insert\u00a0x\u00a0<\/span>Empty<\/span>=<\/span>leaf\u00a0x<\/span><\/li>\n
      4. insert\u00a0x\u00a0<\/span>(<\/span>Node<\/span>\u00a0v\u00a0l\u00a0r<\/span>)<\/span><\/li>\n
      5. \u00a0\u00a0\u00a0\u00a0<\/span>|<\/span>x<\/span>><\/span>v\u00a0<\/span>=<\/span>Node<\/span>\u00a0v\u00a0l\u00a0<\/span>(<\/span>insert\u00a0x\u00a0r<\/span>)<\/span><\/li>\n
      6. \u00a0\u00a0\u00a0\u00a0<\/span>|<\/span>x<\/span><<\/span>v\u00a0<\/span>=<\/span>Node<\/span>\u00a0v\u00a0<\/span>(<\/span>insert\u00a0x\u00a0l<\/span>)<\/span>\u00a0r<\/span><\/li>\n
      7. \u00a0\u00a0\u00a0\u00a0<\/span>|<\/span>otherwise<\/span>=<\/span>Node<\/span>\u00a0x\u00a0l\u00a0r<\/span><\/li>\n<\/ol>\n

        \u662f\u4e0d\u662f\u5f88\u50cf\u5462\u3002\u3002\u3002<\/p>\n

        \u597d\u4e86\u4e0d\u8dd1\u9898\u4e86\uff0c\u8bf4\u8bf4\u4ee3\u7801\u672c\u8eab\u5427\u3002<\/p>\n

        \u51b3\u7b56\u6811\u662f\u5728\u4e00\u5806\u5404\u79cd\u547d\u9898\u5f97\u51fa\u7ed3\u8bba\uff0c\u603b\u4f53\u611f\u89c9\u548cK-Dimensions Tree\u90e8\u5206\u7c7b\u4f3c\uff0c\u5c31\u662f\u4e00\u5806\u7279\u5f81\u627e\u554a\u627e\uff0c\u4e0d\u8fc7\u51b3\u7b56\u6811\u7528\u4e86\u4e00\u4e2a\u53eb\u4fe1\u606f\u71b5\u7684\u73a9\u610f\uff08\u4f3c\u4e4e\u662f\u9999\u519c\u8001\u7237\u5b50\u641e\u7684\u4e1c\u897f\uff1f\u4f46\u662f\u4f5c\u4e3a\u7269\u7406\u7cfb\u5b66\u751f\u603b\u662f\u60f3\u8d77\u6765\u53ef\u7231\u7684\u9ea6\u514b\u65af\u97e6\u5c0f\u5996\u7cbe\uff09\uff0c\u4f7f\u5f97\u6bcf\u6b21\u627e\u4e00\u4e2a\u6700\u77ed\u7684\u5c5e\u6027\u9879\u6765\u5c06\u96c6\u5408\u5212\u5206\u3002ID3\u6bcf\u6b21\u8ba1\u7b97\u4e00\u4e2a\u53eb\u505a\u4fe1\u606f\u589e\u76ca\u7684\u4e1c\u897f\uff0c\u4e5f\u5c31\u662f\u4e0a\u6587\u7684Gain\uff0cGain\u8d8a\u5927\u7684\u5219\u8bf4\u660e\u8fd9\u4e2a\u9009\u9879\u7684\u6709\u6548\u5ea6\u8d8a\u9ad8\uff0c\u5219\u53ef\u4ee5\u53d6\u4e4b\u4e3a\u4fe1\u3002\u4e8e\u662f\u6211\u4eec\u4eceMitchell\u540c\u5fd7\u7f51\u7ad9\u4e0a\u627e\u7684\u6570\u636e\u62ff\u6765\u5b9e\u9a8c\u4e0b\uff08\u987a\u4fbf\u63d0\u4e00\u53e5\uff0ccmu\u7684\u8fd9\u4f4d\u5927\u795e\u628a\u81ea\u5df1\u7684\u4e66\u653e\u5230\u7f51\u4e0a\u516c\u5f00\uff0c\u800c\u4e14\u4ed6\u7684\u6837\u4f8b\u7a0b\u5e8f\u90fd\u662f\u770b\u4e0d\u61c2\u7684Lisp\uff09<\/p>\n

          \n
        1. protected<\/span>\u00a0<\/span>double<\/span>\u00a0<\/span>Gain<\/span>(<\/span>Set<\/span><<\/span>obje<\/span>><\/span>\u00a0data<\/span>,<\/span>int<\/span>\u00a0k<\/span>)<\/span><\/li>\n
        2. \u00a0\u00a0\u00a0\u00a0<\/span>{<\/span><\/li>\n
        3. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>return<\/span>\u00a0<\/span>Entropy0<\/span>(<\/span>data<\/span>,<\/span>k<\/span>)+<\/span>Entropy<\/span>(<\/span>data<\/span>,<\/span>k<\/span>);<\/span><\/li>\n
        4. \u00a0\u00a0\u00a0\u00a0<\/span>}<\/span><\/li>\n<\/ol>\n

          Gain\u662f\u8fd9\u4e48\u4e00\u4e2a\u4e1c\u897f\uff0cEntropy0\u662fdata\u5bf9\u4e8e\u67d0\u4e00\u5c5e\u6027\u7684\u71b5\uff0cEntropy\u662f\u8be5\u5c5e\u6027\u5bf9\u4e8e\u6bcf\u4e00\u503c\u71b5\u7684\u548c<\/p>\n

            \n
          1. protected<\/span>\u00a0<\/span>double<\/span>\u00a0<\/span>Entropy0<\/span>(<\/span>Set<\/span><<\/span>obje<\/span>><\/span>\u00a0data<\/span>,<\/span>int<\/span>\u00a0k<\/span>)<\/span><\/li>\n<\/ol>\n
              \n
            1. \u00a0\u00a0\u00a0\u00a0<\/span>{<\/span><\/li>\n
            2. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>HashMap<\/span>\u00a0<\/span><<\/span>String<\/span>,<\/span>Integer<\/span>><\/span>\u00a0hm<\/span>=<\/span>new<\/span>\u00a0<\/span>HashMap<\/span><<\/span>String<\/span>,<\/span>Integer<\/span>>();<\/span><\/li>\n
            3. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>int<\/span>\u00a0len<\/span>=<\/span>data<\/span>.<\/span>size<\/span>();<\/span><\/li>\n
            4. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>int<\/span>\u00a0i<\/span>=<\/span>0<\/span>;<\/span><\/li>\n
            5. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>double<\/span>\u00a0res<\/span>=<\/span>0<\/span>,<\/span>temp<\/span>;<\/span><\/li>\n
            6. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>double<\/span>\u00a0up<\/span>=<\/span>0<\/span>,<\/span>down<\/span>=<\/span>0<\/span>;<\/span><\/li>\n
            7. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>for<\/span>(<\/span>obje\u00a0obj<\/span>:<\/span>data<\/span>)<\/span><\/li>\n
            8. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span>(<\/span>obj<\/span>.<\/span>res<\/span>)<\/span><\/li>\n
            9. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0up<\/span>++;<\/span><\/li>\n
            10. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>else<\/span><\/li>\n
            11. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0down<\/span>++;<\/span><\/li>\n
            12. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>return<\/span>\u00a0<\/span>-(<\/span>up<\/span>\/(<\/span>up<\/span>+<\/span>down<\/span>)*<\/span>log2<\/span>(<\/span>up<\/span>\/(<\/span>up<\/span>+<\/span>down<\/span>))<\/span><\/li>\n
            13. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>+<\/span>down<\/span>\/(<\/span>up<\/span>+<\/span>down<\/span>)*<\/span>log2<\/span>(<\/span>down<\/span>\/(<\/span>up<\/span>+<\/span>down<\/span>)));<\/span><\/li>\n
            14. \u00a0\u00a0\u00a0\u00a0<\/span>}<\/span><\/li>\n
            15. \u00a0<\/span><\/li>\n
            16. \u00a0\u00a0\u00a0\u00a0<\/span>protected<\/span>\u00a0<\/span>double<\/span>\u00a0<\/span>Entropy<\/span>(<\/span>Set<\/span><<\/span>obje<\/span>><\/span>\u00a0data<\/span>,<\/span>int<\/span>\u00a0k<\/span>)<\/span><\/li>\n
            17. \u00a0\u00a0\u00a0\u00a0<\/span>{<\/span><\/li>\n
            18. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>HashMap<\/span>\u00a0<\/span><<\/span>String<\/span>,<\/span>HashSet<\/span><<\/span>obje<\/span>>><\/span>\u00a0hm<\/span>=<\/span>new<\/span>\u00a0<\/span>HashMap<\/span><<\/span>String<\/span>,<\/span>HashSet<\/span><<\/span>obje<\/span>>>();<\/span><\/li>\n
            19. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>double<\/span>\u00a0len<\/span>=<\/span>data<\/span>.<\/span>size<\/span>();<\/span><\/li>\n
            20. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>int<\/span>\u00a0i<\/span>=<\/span>0<\/span>;<\/span><\/li>\n
            21. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>double<\/span>\u00a0res<\/span>=<\/span>0<\/span>,<\/span>temp<\/span>;<\/span><\/li>\n
            22. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>for<\/span>(<\/span>obje\u00a0tem<\/span>:<\/span>data<\/span>)<\/span><\/li>\n
            23. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span>(<\/span>hm<\/span>.<\/span>get<\/span>(<\/span>tem<\/span>.<\/span>field<\/span>[<\/span>k<\/span>])==<\/span>null<\/span>)<\/span><\/li>\n
            24. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>{<\/span><\/li>\n
            25. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>HashSet<\/span><<\/span>obje<\/span>><\/span>\u00a0set<\/span>=<\/span>new<\/span>\u00a0<\/span>HashSet<\/span><<\/span>obje<\/span>>();<\/span><\/li>\n
            26. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0set<\/span>.<\/span>add<\/span>(<\/span>tem<\/span>);<\/span><\/li>\n
            27. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0hm<\/span>.<\/span>put<\/span>(<\/span>tem<\/span>.<\/span>field<\/span>[<\/span>k<\/span>],<\/span>set<\/span>);<\/span><\/li>\n
            28. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>}<\/span><\/li>\n
            29. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>else<\/span><\/li>\n
            30. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0hm<\/span>.<\/span>get<\/span>(<\/span>tem<\/span>.<\/span>field<\/span>[<\/span>k<\/span>]).<\/span>add<\/span>(<\/span>tem<\/span>);<\/span><\/li>\n
            31. \u00a0<\/span><\/li>\n
            32. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>Set<\/span><<\/span>Map<\/span>.<\/span>Entry<\/span><<\/span>String<\/span>,<\/span>HashSet<\/span><<\/span>obje<\/span>>>><\/span>\u00a0set\u00a0<\/span>=<\/span>\u00a0hm<\/span>.<\/span>entrySet<\/span>();<\/span><\/li>\n
            33. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>double<\/span>\u00a0up<\/span>,<\/span>down<\/span>;<\/span><\/li>\n
            34. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>for<\/span>(<\/span>Map<\/span>.<\/span>Entry<\/span><<\/span>String<\/span>,<\/span>\u00a0<\/span>HashSet<\/span><<\/span>obje<\/span>>><\/span>\u00a0entry<\/span>:<\/span>\u00a0set<\/span>)<\/span><\/li>\n
            35. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>{<\/span><\/li>\n
            36. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0up<\/span>=<\/span>0<\/span>;<\/span>down<\/span>=<\/span>0<\/span>;<\/span><\/li>\n
            37. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>HashSet<\/span><<\/span>obje<\/span>><\/span>\u00a0set2<\/span>=<\/span>entry<\/span>.<\/span>getValue<\/span>();<\/span><\/li>\n
            38. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>for<\/span>(<\/span>obje\u00a0ob1<\/span>:<\/span>set2<\/span>)<\/span><\/li>\n
            39. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>{<\/span><\/li>\n
            40. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>if<\/span>(<\/span>ob1<\/span>.<\/span>res<\/span>)<\/span><\/li>\n
            41. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0up<\/span>++;<\/span><\/li>\n
            42. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>else<\/span><\/li>\n
            43. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0down<\/span>++;<\/span><\/li>\n
            44. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>}<\/span><\/li>\n
            45. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>double<\/span>\u00a0t<\/span>=<\/span>up<\/span>\/(<\/span>up<\/span>+<\/span>down<\/span>)*<\/span>log2<\/span>(<\/span>up<\/span>\/(<\/span>up<\/span>+<\/span>down<\/span>))<\/span><\/li>\n
            46. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>+<\/span>down<\/span>\/(<\/span>up<\/span>+<\/span>down<\/span>)*<\/span>log2<\/span>(<\/span>down<\/span>\/(<\/span>up<\/span>+<\/span>down<\/span>));<\/span><\/li>\n
            47. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0res<\/span>+=(<\/span>up<\/span>+<\/span>down<\/span>)\/<\/span>len<\/span>*<\/span>t<\/span>;<\/span><\/li>\n
            48. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>}<\/span><\/li>\n
            49. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span>return<\/span>\u00a0res<\/span>;<\/span><\/li>\n
            50. \u00a0\u00a0\u00a0\u00a0<\/span>
              \n<\/span><\/li>\n<\/ol>\n

              \u5177\u4f53\u71b5\u4ec0\u4e48\u7684\u53bb\u770bMitchell\u5927\u795e\u7684\u4e66\u5566\u3002\u3002\u8981\u6253\u624e\u5b9e\u57fa\u7840\u54e6\uff08\u5176\u5b9e\u662f\u56f0\u4e86\u6539\u5929\u518d\u5199\uff09\u53cd\u6b63\u8fd9\u73a9\u610f\u8d8a\u5927\u5219\u6570\u636e\u5c31\u5206\u5316\u660e\u663e\u3002<\/p>\n

              \u6bd4\u5982\u8fd9\u4e2a\u6570\u636e<\/p>\n

                \n
              1. 0 \u00a0 \u00a0 1 \u00a0 \u00a02 \u00a0 3 \u00a0 4 \u00a0 5<\/li>\n
              2. {<\/span>“sunny”<\/span>,<\/span>“hot”<\/span>,<\/span>“high”<\/span>,<\/span>“weak”<\/span>,<\/span>“0”<\/span>},<\/span><\/li>\n
              3. {<\/span>“sunny”<\/span>,<\/span>“hot”<\/span>,<\/span>“high”<\/span>,<\/span>“strong”<\/span>,<\/span>“0”<\/span>},<\/span><\/li>\n
              4. {<\/span>“overcast”<\/span>,<\/span>“hot”<\/span>,<\/span>“normal”<\/span>,<\/span>“weak”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
              5. {<\/span>“rain”<\/span>,<\/span>“mild”<\/span>,<\/span>“high”<\/span>,<\/span>“weak”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
              6. {<\/span>“rain”<\/span>,<\/span>“cool”<\/span>,<\/span>“normal”<\/span>,<\/span>“weak”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
              7. {<\/span>“rain”<\/span>,<\/span>“cool”<\/span>,<\/span>“normal”<\/span>,<\/span>“strong”<\/span>,<\/span>“0”<\/span>},<\/span><\/li>\n
              8. {<\/span>“overcast”<\/span>,<\/span>“cool”<\/span>,<\/span>“normal”<\/span>,<\/span>“strong”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
              9. {<\/span>“sunny”<\/span>,<\/span>“mild”<\/span>,<\/span>“high”<\/span>,<\/span>“weak”<\/span>,<\/span>“0”<\/span>},<\/span><\/li>\n
              10. {<\/span>“sunny”<\/span>,<\/span>“cool”<\/span>,<\/span>“normal”<\/span>,<\/span>“weak”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
              11. {<\/span>“rain”<\/span>,<\/span>“mild”<\/span>,<\/span>“normal”<\/span>,<\/span>“weak”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
              12. {<\/span>“sunny”<\/span>,<\/span>“mild”<\/span>,<\/span>“normal”<\/span>,<\/span>“strong”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
              13. {<\/span>“overcast”<\/span>,<\/span>“mild”<\/span>,<\/span>“high”<\/span>,<\/span>“strong”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
              14. {<\/span>“overcast”<\/span>,<\/span>“hot”<\/span>,<\/span>“normal”<\/span>,<\/span>“weak”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
              15. {<\/span>“rain”<\/span>,<\/span>“mild”<\/span>,<\/span>“high”<\/span>,<\/span>“strong”<\/span>,<\/span>“0”}<\/span><\/li>\n<\/ol>\n

                \u65e0\u59a8\u8ba4\u4e3a\uff08\u5e7b\u60f3\u4e3a\uff09\u662fxuhao\u51fa\u53bb\u548c\u59b9\u7eb8\u7ea6\u4f1a\u7684\u6545\u4e8b<\/p>\n

                0\uff5e4\u5c5e\u6027\u5206\u522b\u4ee3\u8868\u5929\u6c14\u7684\u5404\u79cd\u60c5\u51b5\uff0c\u9633\u5149\uff0c\u6e29\u5ea6\uff0c\u6e7f\u5ea6\uff0c\u98ce\u901f\uff0c0or1\u4ee3\u8868\u662f\u5426\uff08\u5e7b\u60f3\uff09\u53bb\u7ea6\u4f1a\u3002<\/p>\n

                \u7136\u540eJre\u53bb\u627e\u4e86mathematica\u7b80\u5355\u7684\u5904\u7406\u4e86\u81ea\u5df1\u7684\u6570\u636e\u544a\u8bc9\u6211\u4eec\u8fd9\u6837\u7684\u7ed3\u679c<\/p>\n

                 <\/p>\n

                \"treedata\"<\/a><\/p>\n

                 <\/p>\n

                \u55ef\uff0c\u4e00\u9897\u6811\uff01\uff0c\u8fd9\u5c31\u662f\u4ea7\u751f\u51b3\u7b56\u7684\u6811\u5566\uff0c\u6211\u4eec\u53ef\u4ee5\u770b\u5230\uff0c\u53ea\u8981overcast\u4e86\uff0cxuhao\u5c31\u4f1a\u4e0d\u7531\u81ea\u4e3b\uff0c\u4f46\u8fd8\u6709\u5176\u4ed6\u53ef\u80fd\u3002\u4f46\u662f\u6709\u51e0\u4e2a\u6709\u8da3\u7684\u95ee\u9898\uff0c\u5176\u4e00\u662f\u6211\u4eec\u66f4\u6539\u4e0b\u6570\u636e<\/p>\n

                \u6bd4\u5982\uff0c\u52a0\u4e00\u4e2a\u9519\u7684\uff01<\/p>\n

                \u52a0\u4e0a\u8fd9\u4e2a<\/p>\n

                {“overcast”,”cool”,”normal”,”weak”,”0″}<\/p>\n

                \uff08\u6211\u4eec\u8ba4\u4e3a\u8fd9\u4e2a\u662f\u9519\u7684\u54c8\uff0c\u56e0\u4e3a\u6839\u636e\u5e38\u8bc6cool\u7684\u5929\u6c14\u66f4\u4e50\u4e8e\u51fa\u53bb\u73a9\uff0c\u4e0a\u9762\u7684\u5224\u65ad\u8fd9\u4e2a\u65e0\u8bba\u5982\u4f55\u4e5f\u8981\u53bb\u7ea6\u59b9\u7eb8\uff0c\u53ea\u80fd\u662f\u5176\u4ed6\u539f\u56e0\u6bd4\u5982\u5403\u8c46\u89d2\u4f4f\u533b\u9662\u8fd9\u79cd\u4e0d\u53ef\u6297\u62d2\u56e0\u7d20\u5f15\u8d77\u7684\uff0c\u90a3\u4e48\u5c31\u662f\u8bef\u5dee\u4e86\uff01\uff09<\/p>\n

                \u4f46\u662f\u5462\uff0c\u6811\u5c31\u53d8\u7684\u4e0d\u53ef\u7406\u89e3\u4e86<\/p>\n

                \"treedatawrong\"<\/a><\/p>\n

                 <\/p>\n

                \u8fd9\u662f\u4ec0\u4e48\u5bb6\u4f19\uff01\u90fd\u662f\u4e9b\u4ec0\u4e48\u7ed3\u8bba\u561b\uff0c\u672c\u6765\u7ea6\u59b9\u7eb8\u641e\u7684\u83ab\u540d\u5947\u5999\u3002<\/p>\n

                \u518d\u6bd4\u5982\uff0c\u5077\u5077\u52a0\u4e00\u5217<\/p>\n

                  \n
                1. {<\/span>“1”<\/span>,<\/span>“sunny”<\/span>,<\/span>“hot”<\/span>,<\/span>“high”<\/span>,<\/span>“weak”<\/span>,<\/span>“0”<\/span>},<\/span><\/li>\n
                2. {<\/span>“2”<\/span>,<\/span>“sunny”<\/span>,<\/span>“hot”<\/span>,<\/span>“high”<\/span>,<\/span>“strong”<\/span>,<\/span>“0”<\/span>},<\/span><\/li>\n
                3. {<\/span>“3”<\/span>,<\/span>“overcast”<\/span>,<\/span>“hot”<\/span>,<\/span>“normal”<\/span>,<\/span>“weak”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
                4. {<\/span>“4”<\/span>,<\/span>“rain”<\/span>,<\/span>“mild”<\/span>,<\/span>“high”<\/span>,<\/span>“weak”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
                5. {<\/span>“5”<\/span>,<\/span>“rain”<\/span>,<\/span>“cool”<\/span>,<\/span>“normal”<\/span>,<\/span>“weak”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
                6. {<\/span>“6”<\/span>,<\/span>“rain”<\/span>,<\/span>“cool”<\/span>,<\/span>“normal”<\/span>,<\/span>“strong”<\/span>,<\/span>“0”<\/span>},<\/span><\/li>\n
                7. {<\/span>“7”<\/span>,<\/span>“overcast”<\/span>,<\/span>“cool”<\/span>,<\/span>“normal”<\/span>,<\/span>“strong”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
                8. {<\/span>“8”<\/span>,<\/span>“sunny”<\/span>,<\/span>“mild”<\/span>,<\/span>“high”<\/span>,<\/span>“weak”<\/span>,<\/span>“0”<\/span>},<\/span><\/li>\n
                9. {<\/span>“9”<\/span>,<\/span>“sunny”<\/span>,<\/span>“cool”<\/span>,<\/span>“normal”<\/span>,<\/span>“weak”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
                10. {<\/span>“10”<\/span>,<\/span>“rain”<\/span>,<\/span>“mild”<\/span>,<\/span>“normal”<\/span>,<\/span>“weak”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
                11. {<\/span>“11”<\/span>,<\/span>“sunny”<\/span>,<\/span>“mild”<\/span>,<\/span>“normal”<\/span>,<\/span>“strong”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
                12. {<\/span>“12”<\/span>,<\/span>“overcast”<\/span>,<\/span>“mild”<\/span>,<\/span>“high”<\/span>,<\/span>“strong”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
                13. {<\/span>“13”<\/span>,<\/span>“overcast”<\/span>,<\/span>“hot”<\/span>,<\/span>“normal”<\/span>,<\/span>“weak”<\/span>,<\/span>“1”<\/span>},<\/span><\/li>\n
                14. {<\/span>“14”<\/span>,<\/span>“rain”<\/span>,<\/span>“mild”<\/span>,<\/span>“high”<\/span>,<\/span>“strong”<\/span>,<\/span>“0”<\/span>}<\/span><\/li>\n<\/ol>\n

                  \u6beb\u65e0\u8fdd\u548c\u611f\uff0c\u4e0d\u8fc7\u662f\u52a0\u4e86\u4e2a\u65e5\u671f\u561b\uff0c\u53ef\u662f\u3002\u3002\u6811\u53d8\u6210\u4e86\u8fd9\u6837\u5b50<\/p>\n

                  \"treedata2\"<\/a><\/p>\n

                   <\/p>\n

                  \u54df\uff0c\u679c\u7136\u65e5\u671f\u7684\u4fe1\u606f\u589e\u76ca\u591f\u5927\u4e86\uff0c\u4f46\u662f\u4e00\u70b9\u90fd\u4e0d\u53ef\u7231\u4e86\u561b\uff01\u65e5\u671f\u662f\u5b8c\u5168\u6b63\u786e\u7684\u7b26\u5408\u4e86\u6570\u636e\uff0c\u4f46\u662f\uff01\u8fd9\u4e0d\u662f\u660e\u663e\u6211\u4eec\u60f3\u8981\u7684\u9884\u6d4b\u3002<\/p>\n

                  \u518d\u6709\u3002\u3002\u4e0a\u9762\u6316\u4e86\u4e2a\u5751\u5728\u5efa\u6811\u768427\u884c\u6beb\u4e0d\u8d1f\u8d23\u7684\u6253\u4e86\u4e2areturn\uff0c\u4e5f\u5c31\u662f\u8bf4\uff0c\u53ea\u8981\u6570\u636e\u9519\u8bef\u5c31\u4f1a\u8e66\u51fa\u6765NullPointer\u4e00\u7c7b\u7684\uff0c\u8fd9\u663e\u7136\u4e0d\u662f\u4e00\u4e2a\u7269\u7406\u7cfb\u5b66\u751f\u6240\u80fd\u5bb9\u5fcd\u7684\u4e25\u8c28\uff08\u5927\u96fe\u8bd5\u9a8c\u8bef\u5dee\u4e09\u500d\u4e5f\u5f97\u7ed9\u4ed6\u5206\u6790\u6210\u5929\u65f6\u5730\u5229\u4eba\u548c\u5fc3\u60c5\u4e0d\u597d\u88ab\u59b9\u7eb8\u7529\u4e86\u5929\u4e0a\u6709\u98de\u789f\u4e0b\u6708\u6709\u6d41\u661f\u51fa\u73b0\u7684\u8bef\u5dee\uff0c\u8fd9\u79cd\u8bef\u5dee\u80fd\u4e0d\u5904\u7406\uff1f\uff09<\/p>\n

                  \u4e8e\u662f\u6709\u4e2a\u53ebC4.5\u7684\u4e1c\u897f\u51fa\u73b0\u4e86\u3002<\/p>\n

                  \u56f0\u4e86\u3002\u3002\u6b32\u77e5\u540e\u4e8b\u5982\u4f55\uff0c\u8bf7\u89c1\u4e0b\u56de\u5206\u6653\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"

                  \u6700\u8fd1\u5b66\u4e60Machine Learning \uff0c\u53d1\u89c9\u9887\u4e3a\u6709\u8da3\u3002\u51c6\u5907\u4f7f\u7528\u76f8\u5173\u7b97\u6cd5\u6765\u8dd1\u4e00\u8dd1\u57fa\u56e0\u7ec4\uff0c\u505a\u505a\u673a\u5668\u4eba\u7684\u63a7\u5236\u3002 … <\/p>\n

                  \u7ee7\u7eed\u9605\u8bfb\u201c\u51b3\u7b56\u6811\u7b97\u6cd5\u521d\u5c1d\u4e4bID3\u201d<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[2],"tags":[],"_links":{"self":[{"href":"http:\/\/blog.xuhao1.me\/index.php?rest_route=\/wp\/v2\/posts\/4"}],"collection":[{"href":"http:\/\/blog.xuhao1.me\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/blog.xuhao1.me\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/blog.xuhao1.me\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/blog.xuhao1.me\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4"}],"version-history":[{"count":7,"href":"http:\/\/blog.xuhao1.me\/index.php?rest_route=\/wp\/v2\/posts\/4\/revisions"}],"predecessor-version":[{"id":107,"href":"http:\/\/blog.xuhao1.me\/index.php?rest_route=\/wp\/v2\/posts\/4\/revisions\/107"}],"wp:attachment":[{"href":"http:\/\/blog.xuhao1.me\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/blog.xuhao1.me\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/blog.xuhao1.me\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}